Mariel Zagunis

The daughter of two Olympic rowers who competed in the 1976 Montreal Games, Mariel Zagunis, 27, was crushed after she failed to qualify for the 2004 Olympics in Athens. But a last-minute spot opened up, and Zagunis took full advantage: she became the first U.S. fencer in a century to win gold. She repeated her individual gold in Beijing in the sabre discipline and added a bronze in the team event. Zagunis has helped raise the profile of her sport as well: she won world titles in 2009 and 2010, and one of her sponsors, TD Ameritrade, featured her in a Times Square billboard this spring.